Sanding vs. stripping Leather seats

In the next few weeks I hope to change the color on seats in the jag from black to tan. The last time I did this, I removed all the color, down to the raw leather using only spirits. The work went surprisingly fast with good results. Lately several listers have suggested sanding the color off and using spirits only for stubborn spots.

Does anyone prefer one way vs. the other and if so, why.